Circuit breaker with improved trip means



Oct. 19, 1965 w. J. POWELL CIRCUIT BREAKER WITH IMPROVED TRIP MEANS Filed April 3, 1963 4 Sheets-Sheet 1 Fig.2.

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INVENTOR William J. Powell BY MAM/a4 ATTORNEY Oct. 19, 1965 w. J. POWELL CIRCUIT BREAKER WITH IMPROVED TRIP MEANS 4 Sheets-Sheet 2 Filed April 3, 1963 Oct. 19, 1965 w J POWELL 3,213,220

CIRCUIT BREAKER WITH IMPROVED TRIP MEANS Filed April 5, 1963 4 Sheets-Sheet 3 Flg. l2. Flg ll Fig. I4

Oct. 19, 1965 w. J. POWELL 3,213,220

CIRCUIT BREAKER WITH IMPROVED TRIP MEANS Filed April 5, 1963 Fig. l5. g Fig. l8; '75 [5| I73) Fig. 9. Fig. 20.

4 Sheets-Sheet 4 United States Patent 3,213,220 CIRCUIT BREAKER WITH IMPROVED TRIP MEANS William .1. Powell, Industry, Pa., assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Apr. 3, 1963, Ser. No. 270,335 9 Claims. (Cl. 200-50) This invention relates to a unitary single-pole circuit breaker that is constructed in such a manner that it can be readily connected to one or more similar unitary singlepole circuit breakers to form a multi-pole circuit breaker. More particularly, this invention relates to a multi-pole circuit breaker comprising a plurality of single-pole circuit breakers that are operatively connected together, each of which single-pole circuit breakers is manufactured as a self-contained independently operable unit.

An object of this invention is to provide an improved single-pole circuit breaker that is adapted for use with one or more similar circuit breakers to constitute a multipole circuit breaker, which single-pole circuit breaker comprises improved automatic interrupting means for effecting automatic opening of all of the poles of the multi-pole circuit breaker.

Another object of this invention is to provide a multipole circuit breaker com-prising a plurality of single-pole circuit breakers with improved means for automatically opening all of the pole units upon the occurrence of a predetermined overload current condition in any of the pole units.

The invention both as to structure and operation, together with additional objects and advantages thereof, will be best understood from the following detailed description when read in conjunction with the accompanying drawings.

In said drawings:

FIGURE 1 is a view, in side elevation, of a single pole circuit breaker constructed in accordance with principles of this invention;

FIG. 12 is a top view of the circuit breaker shown in FIG. 1;

FIG. 3 is an enlarged elevational view, with one of the insulating side plates removed, of the circuit-breaker mechanism;

FIG. 4 is a top view of the mechanism shown in FIG. 3, with both of the side plates being shown, and with the operating handle and associated parts being removed for the purpose of clarity;

FIG. 5 is an elevational view of one of the insulating side plates shown in FIGS. 3 and 4;

FIGS. 6, 7 and 8 are elevational, end and top views, respectively, of one of the supporting clips shown in FIG. 4;

FIGS. 9 and 10 are elevational and end views, respectively, of the main latch member shown in FIG. 3;

FIGS. 11 and 12 are elevational and end views, respectively, of the latch and trip member shown in FIG. 3;

FIGS. 13 and 14 are end and elevational views, respectively, of the armature member shown in FIG. 3;

FIG. 15 is a top view of one of the plates of the arcextinguishing structure shown in FIGS. 3 and 4;

FIG. 16 is a top view of a three-pole circuit breaker constructed in accordance with principles of this invention;

FIG. 17 is a top view of a two-pole circuit breaker constructed in accordance with principles of this invention;

FIG. 18 is an elevational view of one of the handle ties shown in FIGS. 16 and 17; and

FIGS. 19 and 20 are elevational and end views, re-

spectively, of one of the connecting members shown in FIGS. 16 and 17.

Certain features of the circuit breakers that are herein illustrated are described and claimed in the copending application of Russell C. Strother et al., Ser. No. 111,313, filed May 19, 1961, now Patent No. 3,174,024 issued Mar. 16, 1965, and also in the copending application of Hiller D. Dorfman et al., Ser. No. 112,172, filed May 19, 1961, both of which applications have been assigned to the assignee of the instant application.

Referring to the drawings, a circuit breaker 3 is shown in FIGS. 1 and 2 comprising a housing 5 of molded ins'iilating material, and a unitary circuit-breaker mechanism 7 supported within the housing. As is seen in FIG. 2, the housing 5 comprises two halves 9 and 11 that are secured together by means of four tubular rivets 12 (FIGS. 1 and 2).

The unitary circuit-breaker mechanism 7, FIGS. 3 and 4, comprises a contact structure 13, an arc-extinguishing structure 15, an operating mechanism 17 and a tripping mechanism 19. The circuit-breaker mechanism is supported between two insulating side plates 21, one of which side plates 21 is shown in detail in FIG. 5.

The contact structure 13 comprises a stationary contact 23 and two movable contacts 25, only one of the movable contacts 25 being shown in FIG. 3. Each of the movable contacts 25 is supported on one end of a movable contact arm 27 (FIGS. 3 and 4). One end of a tension spring 29 is supported at the other ends of the two movable contact arms 27 on a pin 31 that connects the two movable contact arms. The other end of the spring 29 is attached to a pin 33 that is supported in openings 35 (FIG. 5) in the two insulating side plates 21. The pin 33 is positioned in suitable slots in the movable contact arms 27 so that the movable contact arms 27 can move relative to the pin 33 when the contact arms are in the closed position. The spring 29 biases the contact arms 27 about a pivot pin 37 to provide contact pressure when the contacts 23, 25 are in the closed position.

The operating mechanism 17 includes a toggle, comprising a lower toggle link 38 that is pivotally connected to the movable contact arms 27 intermediate the ends of the contact arms 27 by means of the pivot pin 37. An upper toggle link 39 is connected at one end to the upper end of the lower toggle link 38 by means of a knee pivot pin 41. The upper end of the upper toggle link 39 is pivotally connected to a releasable latch member 43 by means of a pivot pin 45. The releasable member 43 is pivotally supported between the insulating side plates 21 by means of a pivot pin 47 that is supported in openings 49 (FIG. 5) in the side plates 21.

An operating member 51, having an inverted U shaped construction, is pivotally supported on the insulating side plates 21 in grooves 53 (FIG. 5). The legs of the U- shaped member 51 are prevented from moving off of the top surface of the insulating side plates 21 by means of clips 55 (FIGS. 6-8) each of which clips is held in place by the pin 33 (FIGS. 3 and 4). The pin 33 extend-s through an opening 59 (FIG. 6) in each of the clips 55 and is riveted over at its ends as seen in FIG. 4. Each of the clips 55 has an opening 61 (FIG. 8) therein for receiving one of the legs of the U-shaped member 51.

An operating handle 63, of molded insulating material, is supported at the outer end of the Ushaped member 51. An arcuate portion 65 of the operating handle 63 substantially closes an opening in the molded housing 5 (FIGS. 1 and 2) through which the operating handle 63 extends. Four springs 67 (only two of which are shown in FIG. 3) are connected at one end to two plates 68 (only one being shown in FIG. 3) that are connected to the knee pivot 41 of the toggle link 38, 39. The springs 67 are connected at their other ends to an inverted U-shaped plate 69 that is supported at the outer end of the U-shaped member 51.

The contacts 23, are manually opened by movement of the operating handle 63 in a counterclockwise (FIG. 3) direction to the 011 position. This movement carries the line of the action of the over-center springs 67 to the left of the pivot 41 causing collapse of the toggle 38, 39. As the toggle 38, 39 collapses the switch arms 27 first move to engage the pin 33 and thereafter the switch arms 27 rotate counterclockwise about the pin 33 to open the contacts 23, 25 with a snap action. Opening movement of the contact arms 27 is limited by engagement of the contact arms with a pin 70 (FIGS. 3 and 4) which pin 70 is supported in openings 71 (FIG. 5) in the side plates 21. Reverse or clockwise movement of the operating handle 63 to the on" position moves the knee pivot 41 of the toggle 38, 39 to the right (FIG. 3) resetting the toggle 38, 39 and moving the contact arms 27 back to the closed position, shown in FIG. 3, with a snap action.

The trip structure 19 comprises a latch member 73 that is seen in detail in FIGS. 11 and 12. The latch member 73 comprises a generally cylindrical trip bar 75 having a notch 77 therein, and a trip arm 79 having a flag portion 81 at the top thereof. The trip bar 75 is rotatably supported in openings 83 (FIG. 5) in the side plates 21. The ends of the trip bar 85 are cut away at 86 for a purpose to be hereinafter specifically described.

A main latch 87, which is seen in detail in FIGS. 9 and 10, comprises a pin 88 that is rotatably supported in openings 89 (FIG. 5) in the side plates 21. The main latch 87 has a latch portion 91 that engages a latch portion 93 (FIG. 3) on the releasable member 43 to hold the releasable member 43 in the latched position. The main latch 87 has a portion 95 that engages the periphery of the trip bar 75 just opposite the notch 77 (FIG. 12) when the parts are in the latched position (FIG. 3). The trip member 73 is biased in a counterclockwise direction (FIG. 3) by means of a torsion spring 97. The main latch 87 is biased in a counterclockwise direction by means of a torsion spring 99.

An armature member 101 (seen in detail in FIGS. 13 and 14) comprises a pin 103 and a member 105 that has an armature 107 disposed at one end thereof and a projection 109 at the other end. The pin 103 of the armature member 101 is rotatably supported in openings 111 (FIG. 5) in the insulating side plates 21. The armature member 101 is biased in a counterclockwise direction (FIG. 3) by means of a torsion spring 112.

A bimetallic member 115 is attached at one end to a conductor 117. The free end of the bimetal 115 has a projection 119 thereon having a tapped opening through which an adjusting or calibrating screw 121 extends. A U-shaped magnetic yoke 123 is attached to the conductor 117 opposite the armature 107.

The circuit through the circuit breaker mechanism (FIG. 3) extends from a conductor 127 that is attached at one end to the upper end of the conductor 117, through the conductor 117, flexible conductors 129 that are attached at one end to the conductor 117 and at the other end to the contact arms 27, the contact arms 27, the contacts 23, 25 and a conductor 131.

Solderless terminal connectors 132 (FIG. 1), of a type well known in the art, are attached to the outer ends of the conductors 127 and 131 and are provided to enable connection of the circuit breaker 3 in an electrical circuit in a manner well known in the art.

The conductor 117 has three projections 133 (FIG. 3) at each side thereof which projections fit in openings 134 (FIG. 5) in the side plates 21 to support the conductor 117, and the parts that are connected thereto, on the side plates 21. The conductor 131 has two projections 135 A and 136 (FIG. 3) at each side thereof which projections fit in openings 137 and 138 (FIG. 5), respectively, in the side plates 21 to support the conductor 131 and the parts that are connected to the conductor 131, on the side plates 21.

Two openings 139 (FIG. 5) are provided in each of the side plates 21. When the circut-breaker mechanism '7 (FIGS. 3 and 4) is mounted in the insulating housing 5 (FIGS. 1 and 2), two projections (not shown) that are molded integral with each of the halves 9 and 11 of the insulating housing 5, fit with the openings 139 in the side plates 21 to position and support the circuitbreaker mechanism 7 within the housing.

When an overload current below a predetermined value passes through the circuit breaker, the bimetallic member 115 is heated and it bends to the right (FIG. 3) whereupon the calibrating screw 121 engages the flag portion 81 of the latch member 73 rotating the latch member 73 in a clockwise direction. During this movement, the trip bar 75 is moved to move the notch 77 (FIG. 12) adjacent the part 95 of the main latch 87 permitting the main latch 87 to move clockwise to a tripping position. During this clockwise movement of the main latch 87, the latch portion 91 thereon rotates free of the latch portion 93 of the releasable member 43 to release the member 43. When released, the member 43 rotates clockwise about its pivot 47 under the bias of the springs 67 causing collapse of the toggle 38, 39 and opening of the switch arms 27 about the pivot 33. During this movement, the handle 63 is moved, in a manner well known in the art, to a tripped position intermediate the on and off positions, thereby giving a visual indication that a tripping operation has occurred.

Before the contacts can be closed following an automatic opening operation, it is necessary to reset and relatch the mechanism. This is accomplished by moving the handle 63 in a counterclockwise direction from the intermediate or tripped position to the extreme off position. During this movement, a projection 140 on the U-shaped member 51 engages a shoulder 141 on the releasable member 43 moving the releasable member 43 counterclockwise about its pivot 47. Near the end of this movement, the lower rounder part of the latch portion 93 of the releasable member 43 engages an outwardly extending arm 142 (FIG. 9) on the main latch 87 and moves the main latch to the latching position. As soon as the portion 95 of the main latch 87 clears the edge adjacent the notch 77 (FIG. 12) of the trip bar 75, the torsion spring 97 (FIG. 3) rotates the latch member 73 clockwise to the latched position. The latch portion 91 of the main latch 87 is then in position engaging the latch portion 93 of the releasable member 43 so that upon release of the handle 63, the mechanism is latched and the contacts can be closed in the previously described manner by movement of the handle 63 to the on position.

Upon the occurrence of an overload current above the predetermined value, the magnetic yoke 123 is energized suificiently to attract the armature 107 to rotate the armature 101 clockwise about its pivot 103, whereupon the up per projection 109 on the armature member 101 engages the flag portion 81 of the latch member 73 rotating the latch member 73 clockwise to efiect release of the main latch 87 and release of the releasable member 43 to thereby effect a tripping operation in the same manner hereinbefore described.

When the contacts 23, 25 open, an arc is established between each of the movable contacts 25 and the stationary contact 23. These arcs are extinguished by means of the arc-extinguishing structure 15. The arc-extinguishing structure 15 comprises the two insulating side plates 21, a plurality of arc-extinguishing members or plates 151 (one of which is shown in detail in FIG. 15), an arcrunner plate 152 that is connected to the stationary contact 23, a plate 153 backing up the arc-runner plate 153, two insulating plates 154 and an insulating plate 155. Each of the arc-extinguishing plates 151 has two notches 159 (FIG. therein. Each of the arc-extinguishing plates 151 is supported between the insulating side plates 21 by means of elongated projections 161 (FIG. 15 that fit in the openings 163 (FIG. 5) in the side plates 21. Projections 162 on each side of the arc-runner plate 152 and on each side of the arc-runner supporting plate 153 fit in the openings 138 (FIG. 5) in the insulating side plates 21 to support the plates 152 and 153 on the side plates 21.

During the opening operation, when the contact arms 27 move away from the contact 23, the two arcs established between the two contacts and the contact 23, are magnetically attracted along the arc-runner plate 152 and into the slots 159 (FIG. 15) of the magnetic plates 151 to be broken up into a plurality of serially related are portions, which are portions are rapidly extinguished in a manner well known in the art.

The insulating plates 154 and 155 have projections 171 thereon that engage in openings 137 and 173 (FIG. 5) in the insulating side plates 21 to support the plates 154 and 155 on the side plates 21. These insulating members 153, 155 are provided to block the gases, that are generated upon extinguishment of the arc, from moving back into the operating portion of the circuit breaker.

In FIG. 17, there is illustrated a two pole circuit breaker or circuit interrupter 170 comprising two identical circuit breakers 3 that are secured together in an abutting sideby-side relationship by means of rivets 171 that pass through the tubular rivets 12 of the individual breakers. A handle tie 173' having ends 175 that engage in openings 177 (FIG. 3) in the handles 63, is provided to tie the handles 63 of the circuit breakers 3 together. Thus, both poles of the multi-pole circuit breaker can be simultaneously manually operated to open and close the breaker. Referring to FIG. 4, it will be seen that the ends 85 of the trip bar 75 extend out a short distance from the side plates 21. The tripping mechanisms 19 of both pole units (FIG. 17) of the two-pole circuit breaker are tied to gether by means of a trip bar connecting member 179. The trip bar connecting member 179 has openings 181 (FIGS. 19 and 20) therein which openings are shaped to key with the ends 85 (FIG. 12) of the trip bars 75.

Each half 9 and 11 (FIG. 2) of the molded housing 5 of each of the circuit breakers 3 (FIG. 17) is provided with a knockout 180 (FIG. 1) that is removable to provide access to an end 85 (FIG. 12) of the trip bar 75. As is seen in FIG. 17, when the breakers 3 are connected together the adjacent knockouts 181) (FIG. 1) are removed and the trip bar connecting member 179 is placed in position with the openings 181 therein receiving the adjacent ends 85 of the trip bars 75. With the connecting member 179 in place (FIG. 17) the two trip or latch members 73 (FIGS. 11 and 12) of the two pole units 3 will move as a common unitary trip bar structure, so that upon the occurrence of a tripping overcurrent in either of the pole units 3, both pole units will be automatically opened.

A three-pole circuit breaker or circuit interrupter 185 is shown in FIG. 16 and it comprises three identical circuit breakers 3 fastened together by means of elongated rivets 187 that pass through the tubular rivets 12 of the individual circuit breakers. These three circuit breakers or pole units are tied together by means of two handle ties 173' and two trip-bar connecting members 179 in the same manner as are the two pole units of the two-pole circuit breaker 170 (FIG. 17).

With the provision of a knockout 180 (FIG. 1) in each side of each circuit breaker 3, and with the trip bar 75 having its ends 85 (FIG. 4) extending out through both of the side plates 21, each of the circuit breakers 3 (FIGS. 1, 16 and 17) is adapted to be connected at either side thereof to another circuit breaker. It is to be noted also that each pole unit 3 of the multi-pole circuit breakers and 185, is a unit that is manufactured as a separate and independently operable single-pole circuit breaker and can be utilized as a separate single pole breaker.

In a multi-pole circuit breaker of the type illustrated in FIGS. 16 and 17 wherein each of the pole units comprises a single-pole circuit breaker, if there is sufficient play between the connected tripping latch members 73, or if there is sufficient misalignment of parts, it is possible for the tripping latch 73 of the overloaded pole unit to move to a tripping position without moving the tripping latches 73 of the other pole Units a suflicient distance to effect a. tripping operation in the other pole units. Thus, an additional means is provided to move the tripping latch 73 of the overloaded pole unit an additional distance during a tripping operation so that even if there is some play or misalignment between parts, all of the tripping latches 73 will be moved at least to a tripping position when one of the pole units trips. This additional means comprises a spring 191 (FIGS. 3 and 4) that is attached at one end to the tripping latch 73 and at the other end to the cradle or releasable member 43. As can be seen in FIGS. 3 and 4, the looped ends of the spring 191 are supported in openings in the members 73 and 43. When the releasable member 43 is in the latched position shown in FIG. 3, the spring 191 is not under tension. Thus, there is no force exerted by the spring 191 on the tripping latch 73. A similar spring 191 is provided in each circuit breaker so that when a plurality of the single-pole circuit breakers 3 are connected together (FIGS. 16 and 17) each of the pole units will include a circuit breaker mechanism with a spring 191 therein. When an overload current above a. predetermined value occurs in any of the pole units of the multi-pole circuit breaker (FIGS. 16 and 17), the tripping latch 73 of the overloaded poleunit is moved to a tripping position which movement should ordinarily move all of the tripping latches 73 of all of the pole units simultaneously to the tripping position. When the latch 73 of the overloaded pole unit releases the latch 87 to thereby release the releasable member 43, and the releasable member 43 is pivoted clockwise (FIG. 3) under the force of the operatingv springs 67, this movement of the releasable member 43 will operate through the spring 191 to pull the tripping latch 73 in the overloaded pole unit an additional distance in the tripping direction so that, even if there is some play or misalignment between the parts of the difierent pole units, all of the tripping latches 73 will be moved at least to the tripping position to effect tripping of all of the pole units of the multi-pole circuit breaker.

From the foregoing, it can be understood that there is provided, by this: invention, a multi-pole circuit breaker that comprises a plurality of pole units, each of which pole units is manufactured as a separate single-pole circuit breaker that can be utilized as a separate single-pole circuit breaker. Each of the pole units comprises a circuit breaker having a releasable member and a first latch latching the releasable member, which first latch is in turn latched by means of a second or tripping latch. Each of the tripping latches comprises a rotatable bar, each of which bars is so positioned that it extends out through the associated supporting plates on both sides of the associated circuit breaker mechanism. A knock-out is provided in each side of the housing of each circuit breaker, and with the trip bar of each circuit breaker having its ends extending out through both of the supporting plates of the breaker, each of the circuit breakers is adapted to be connected at either side thereof to another circuit breaker. A spring member is provided in each circuit breaker between the tripping latch and the releasable member so that, when the releasable member of an overloaded pole unit is released, the movement of this mem ber under the force of the operating springs of the overloaded pole unit will operate through the additional spring to move the tripping latch of the overload pole unit an additional distance in the tripping direction. Thus, even if there is some play or misalignment between the parts of the adjacent pole units, all of the tripping latches of the mu-lti-pole circuit breaker will be moved at least to a tripping position so that all of the pole units of the multi-pole circuit breaker Will be tripped when a tripping overload occurs in any of the pole units.

While the invention has been described in accordance with the provisions of the patent statutes, it is to be understood that various changes and modifications may be made in the structural details and arrangements of parts thereof without departing from the spirit of the invention.

I claim as my invention:

1. A subject single-pole circuit breaker comprising an insulating housing and a circuit-breaker mechanism supported within said housing, said circuit-breaker mechanism comprising a pair of contacts and a releasable member moving automatically upon release thereof to eifect automatic opening of said contacts, a first latch structure latching said releasable member, a second latch structure latching said first latch structure, means operable upon the occurrence of an overload current above a predetermined value to operate said second latch structure to release said first latch structure to thereby release said releasable member, said second latch structure comprising means adapted to be operatively connected to a similar second latch structure of a similar circuit breaker when the similar circuit breaker is mounted adjacent the subject circuit breaker whereby operation of said second latch structure will operate said similar second latch structure, and additional means actuated automatically upon said movement of said releasable member for operating said second latch structure.

2. A subject single-pole circuit breaker adapted to be connected to a similar single-pole circuit breaker to form a multi-pole circuit breaker, said subject circuit breaker comprising an insulating housing and a circuit-breaker mechanism supported within said housing, said circuitbreaker mechanism comprising a pair of contacts and a releasable member, upon release of said releasable member means operating automatically to move said releasable member to effect automatic opening of said contacts, a latch structure rotatably supported in a latching position to etfect latching of said releasable member, trip means operable upon the occurrence of an overload current above a predeterminted value to rotate said rotatable latch structure sufficiently to effect release of said releasable member, said rotatable latch structure comprising means adapted to be operatively connected to a similar rotatable latch structure of said similar circuit breaker when said similar circuit breaker is mounted adjacent the subject circuit breaker whereby rotation of said rotatable latch structure Will simultaneously rotate said similar rotatable latch structure, additional trip means, said releaseable member during said movement thereof automatically operating said additional trip means to further rotate said rotatable latch structure.

3. A subject single pole circuit breaker adapted to be connected to a similar single pole circuit breaker to form a multi-pole circuit breaker, said subject single-pole circuit breaker comprising an insulating housing and a circuit-breaker mechanism supported within said hous ing, said circuit-breaker mechanism comprising a pair of contacts and a releasable member releasable to effect automatic opening of said contacts, a first latch structure latching said releasable member, a second latch structure comprising a latch member and a cylindrical bar rotatably supported Within said housing, said first latch structure having a portion thereof engaging the pehiphery of said bar, a notch in said rotatable bar, means operating upon the occurrence of certain overload current conditions to rotate said second latch structure to a tripping position whereupon said portion of said first latch structure is snapped into said notion to effect release of said releasable member, said second latch structure comprising means adapted to be operatively connected to a similar second latch structure of said similar circuit breaker when the similar circuit breaker is mounted adjacent the subject circuit breaker whereby rotation of said second latch structure will rotate said similar second latch structure, additional means comprising a resilient member connected between said releasable member and said second latch structure, and said releasable member when released operating through said resilient member to additionally rotate said second latch structure.

4. A multi-pole circuit breaker wherein each pole comprises a single-pole circuit breaker; each single-pole circuit breaker comp-rising an insulating housing and a circuit-breaker mechanism supported Within said housing, each circuit-breaker mechanism comprising a pair of contacts and a releasable member releasable to effect automatic opening of said contacts, a separate first latch structure latching each releasable member, a separate second latch structure latching each first latch structure, means in each single-pole circuit breaker operable upon the occurrence of an overload current to operate the associated second latch structure to release the associated first latch structure to thereby release the associated releasable member, means operatively connecting adjacent second latching structures whereby all of said second latch structures function as a common trip bar structure movable as a unit to effect release of all of said releasable members, and a separate means connecting each releasable member with the associated second latch structure to provide for further releasing movement of said common trip bar structure upon release of any of said releasable members.

5. A multi-pole circuit breaker wherein each pole comprises a single-pole circuit breaker; each single-pole circuit breaker comprising an insulating housing 'and a circuit-breaker mechanism supported within said housing, each circuit-breaker mechanism comprising a pair of contacts and a releasable member, each circuit breaker mechanism comprising means operating automatically when the associated releasable member is released to effect tripping movement of the associated releasable member to thereby efiect automatic opening of the associated contacts, a separate first latch structure latching each releasable member, a separate second latch structure latching each first latch structure, means in each single-pole circuit breaker operable upon the occurrence of an overload current to operate the associated second latch structure to release the associated first latch structure to thereby release the associated releasable member, means operatively connecting adjacent second latch structures whereby said second latch structures function as a common trip bar structure movable as a unit to effect release of all of said releasable members, and resilient means in each single-pole circuit breaker connecting the associated releasable member with the associated second latch structure to provide for further releasing movement of said common trip bar structure upon tripping movement of any of said releasable members to thereby provide automatic opening of the contacts of all of said single-pole circuit breakers upon the occurrence of an automatic opening operation in any of said single-pole circuit breakers even when there is some play or misalignment of parts between said single-pole circuit breakers.

6. A multi-pole circuit breaker comprising a plurality of pole units each of which pole units comprises a singlepole circuit breaker, each pole unit comprising an insulating housing and a circuit-breaker mechanism supported within the housing, each circuit-breaker mechanism comprising a pair of contacts and a releasable member, each releasable member when released moving the associated contacts, each pole unit comprising a rotatable latch structure latching the associated releasable member, means operatively connecting adjacent rotatable latch structures whereby all of the rotatable latch structures function as a common trip bar structure, each pole unit comprising trip means disposed to operate the associated rotatable latch structure upon the occurrence of an overload in the associated pole unit, each pole unit comprising means connecting the associated releasable member with the associated rotatable latch structure, and upon the occurrence of an overload current above a predetermined value in any pole unit the associated trip means operating to rotate the associated rotatable latch structure to eifect release of the associated releasable member, said released releasable member moving to effect automatic opening of the associated contacts and also moving to operate an associated resilient means to additionally move the associated rotatable latch structure to provide an additional movement of the common trip bar structure.

7. A mulit-pole circuit breaker comprising a plurality of pole units each of which pole units comprises a singlepole circuit breaker, each pole unit comprising an insulating housing and a circuit-breaker mechanism supported Within said housing, each circuit-breaker mechanism comprising a pair of contacts and a releasable member, each releasable member when released moving to effect automatic opening of the associated contacts, a separate rotatable latch structure latching each releasable member, means operatively connecting adjacent latch structures whereby all of the latch structures function as a common rotatable trip bar structure, a separate trip means disposed to rotate each latch structure upon the occurrence of an overload in the associated pole unit, a separate resilient means connecting each releasable member with the associated latch structure, and upon the occurrence of an overload current above a predetermined value in any pole unit the associated trim means operating to rotate the associated latch structure to effect release of the associated releasable member, said released releasable member moving to effect opening of the associated contacts which movement also operates the associated resilient means to additionally rotate the associated latch structure to additionally rotate the common trip bar structure whereby all of said pole units will be more definitely automatically opened upon the occurrence of an overload current above the predetermined value in any of said pole units.

8. A multi-pole circuit breaker comprising, in combination, at least two circuit breakers, each of said circuit breakers comprising an insulating housing and a circuit-breaker mechanism supported within the housing, each of said circuit-breaker mechanisms comprising a stationary contact and a movable contact cooperable therewith to open and close a circuit, an operating handle for each of said circuit-breaker mechanisms, each of said operating handles being manually operable to open and close the associated contacts, each of said circuit-breaker mechanisms comprising a member releasable to eifect automatic opening of the associated contacts, each of said circuit-breaker mechanisms comprising a latch structure rotatable to effect release of the associated releasable member, a separate trip means for automatically rotating each of said latch structures upon the occurrence of abnormal current conditions through the associated circuit breaker to effect release of the associated releasable member, each of said circuit breakers comprising a knockout on each of two opposite sides of the associated insulating housing, each of said knock-out being adjacent one end of the associated latch structu-re, means operatively connecting said circuit breakers together in a sideby-side relationship and comprising a handle tie connecting said handles together, a connecting member connecting adjacent latch structures together when adjacent knockouts are removed, resilient means in each circuit breaker connecting the associated releasable member with the associated latch structure to provide for an additional tripping movement of all of the latch structures upon the release of any of the releasable members.

9. A multi-pole circuit breaker comprising a plurality of pole units, each of said pole units comprising a singlepole circuit breaker, each single-pole breaker comprising an insulating housing and a circuit-breaker mechanism supported Within said housing, each circuit-breaker mechanism comprising a pair of contacts and a releasable member movable upon release thereof to effect automatic opening of the associated contacts, a separate first latch structure latching each releasable member, a separate second latch structure comprising a rotatable cylindrical bar having a notch therein, means biasing each first latch structure against the periphery of the associated cylindrical bar, each single pole circuit breaker comprising a separate trip means automatically operable upon the occurrence of an overload current condition to rotate the asscociated second latch structure whereupon a portion of the associated second latch structure is snapped into the associated notch to thereby effect release of the associated releasable member, means operatively connecting adjacent second latch structures to function as a common trip bar structure, each single-pole circuit breaker comprising a spring member connected at one end to the associated releasable member and at the other end to the associated second latch structure, upon release of any of the releasable members the associated spring member being operated to pull the associated second latch structure to provide that each second latch structure will move sufficiently to move the common trip bar structure to a position wherein all of said releasable members are released.

References Cited by the Examiner UNITED STATES PATENTS 2,015,633 9/35 Dorfman 200-116 2,977,443 3/61 Middendorf 200-116 2,989,606 6/6 1 i/Valker 200-116 KATHLEEN H. CLAFFY, Plil'i'ltll') Examiner.

BERNARD A. GILHEANY, Examiner. 

1. A SUBJECT SINGLE-POLE CIRCUIT BREAKER COMPRISING AN INSULATING HOUSING AND A CIRCUIT-BREAKER MECHANISM SUPPORTED WITHIN SAID HOUSING, SAID CIRCUIT-BREAKER MECHANISM COMPRISING A PAIR OF CONTACTS AND A RELEASABLE MEMBER MOVING AUTOMATICALLY UPON RELEASE THEREOF TO EFFECT AUTOMATIC OPENING OF SAID CONTACTS, A FIRST LATCH STRUCTURE LATCHING SAID RELEASABLE MEMBER, A SECOND LATCH STRUCTURE LATCHING SAID FIRST LATCH STRUCTURE, MEANS OPERABLE UPON THE OCCURRENCE OF AN OVERLOAD CURRENT ABOVE A PREDETERMINED VALUE TO OPERATE SAID SECOND LATCH STRUCTURE TO RELEASE SAID FIRST LATCH STRUCTURE TO THEREBY RELEASE SAID RELEASABLE MEMBER, SAID SECOND LATCH STRUCTURE COMPRISING MEANS ADAPTED TO BE OPERATIVELY CONNECTED TO A SIMILAR SECOND LATCH STRUCTURE OF A SIMILAR CIRCUIT BREAKER WHEN THE SIMILAR CIRCUIT BREAKER IS MOUNTED ADJACENT THE SUBJECT CIRCUIT BREAKER WHEREBY OPERATION OF SAID SECOND LATCH STRUCTURE WILL OPERATE SAID SIMILAR SECOND LATCH STRUCTURE, AND ADDITIONAL MEANS ACTUATED AUTOMATICALLY UPON SAID MOVEMENT OF SAID RELEASABLE MEMBER FOR OPERATING SAID SECOND LATCH STRUCTURE. 